The present invention relates to self-inking rubber stamping devices.
Conventional self-inking or automatic stamps generally comprise a two-part housing, a solid-rubber printing stamp glued to a pivoted, displaceable base plate, and an ink-absorbent pad made of cellular rubber or felt. With light vertical pressure on the upper part of the housing, while the lower part is placed on a paper sheet, a stamping process is performed whereby the stamp, which contacts the ink pad, slides downwards, turns over into an upside-down position, and becomes pressed against the paper.
These devices suffer from numerous disadvantages. Due to the fact that the ink pad is installed face down at an elevated location within the housing, the overall height of the device is necessarily great, in order to leave enough room for the rubber stamp plate to perform a complete 180 degree overturn .
Secondly, the construction was such that the rubber stamp was in constant compressive contact with the ink pad. This continuous pressure on the ink pad caused excessive deformation of the pad which, of course, reduced its efficiency to ink the rubber molded characters of the stamp. If, on the other hand, a more rigid sponge were used as an ink pad, in order to better withstand the prolonged pressure, a print of poor quality would result.
Finally, the construction of the overturning mechanism and of the device as a whole necessitated the incorporation of a great number of parts and components, making the device more costly and less durable.
It is, therefore, the object of the invention to devise a self-inking stamping device that will effectively overcome the above-listed disadvantages.
It is a further object of the invention to reduce the height of the device and to obtain thereby a handy and conveniently operable device.
It is a still further object of the invention to have the ink pad installed in the device in an upright position, namely perpendicular to the printed surface.
It is a still further object of the invention to allow only a short wetting contact between the rubber stamp and the ink pad for every printing cycle, thereby avoiding the continuous compressive contact and the resulting damage to the ink pad.
It is a still further object of the invention to reduce a minimum the number of parts and components which compose the device.